The link between executive functioning deficits and impaired metaphor comprehension in high-functioning autistic spectrum disorders


Studies in neurotypical populations and various clinical populations have implicated executive functioning as playing a pivotal role in the metaphor comprehension process. However, though executive functioning and metaphor comprehension deficits are well attested in autistic spectrum conditions, there is little research on the link between the two in this population. The present study assessed a range of executive function cognitive domains (generativity, set shifting, inhibition, and working memory) as well as tasks examining the ability to identify and explain metaphors in 10 autistic participants without intellectual disability (mean age 24.10 years, 5 females) and 13 non-autistic participants (mean age 26.50 years, 7 females). Results showed significant response inhibition and metaphor identification impairments in the autistic group. Near-significant group differences were also found on the metaphor explanation task, with autistic participants numerically but not significantly more likely to given concrete or incorrect explanations. Higher generativity and response inhibition scores correlated positively and significantly with faster and more accurate metaphor identification, and with a higher quality of metaphor explication in both groups. The effect of group interaction on these correlations was not significant – indicating that both autistic and non-autistic groups had the same profile of executive functioning contribution to metaphor comprehension. The study points to executive functioning deficits as explaining the impairment of and variance in metaphor comprehension in autistic individuals without intellectual disability. (Supervised by Dr. Napoleon Katsos.)

Thesis for MPhil in Applied and Theoretical Linguistics at the University of Cambridge